Fibrous materials of fluororesins and deodorant and antibacterial fabrics made by using the same

ABSTRACT

A fibrous material of fluorine-containing resins such as polytetrafluoroethylene which has a high deodorizing antibacterial activity is obtained. A monofilament, staple fiber, split yarn or finished yarn thereof comprising a fluorine-containing resin such as polytetrafluoroethylene containing a photodegrading catalyst such as an anatase-type titanium dioxide in an amount of from 5 to 50% by weight, and a deodorizing antibacterial woven fabric, knitted fabric, and non-woven fabric which are produced by using the monofilament, staple fiber, split yarn or finished yarn thereof.

TECHNICAL FIELD

The present invention relates to a fibrous material offluorine-containing resin, particularly polytetrafluoroethylenecontaining a photodegrading catalyst and a deodorizing antibacterialcloth produced by using the fibrous material.

BACKGROUND ART

A photodegrading catalyst is a substance which is activated by photoenergy having a short wave length such as light, particularlyultraviolet ray to exhibit catalytical ability for degrading compounds.Examples of known photodegrading catalyst are anatase-type titaniumdioxide (TiO₂), zinc oxide (ZnO), tungsten trioxide (W₂O₃) and the like.It is known that those photodegrading catalysts degrade compoundsemitting malodorous smell and have sterilizing ability, thus being usedfor deodorizing and for antibacterial purpose. In order for thephotodegrading catalysts to exhibit their function effectively, it isnecessary to contact the catalysts directly to harmful substances.However if materials carrying the photodegrading catalysts are organicsubstances, there is a case where the catalysts degrade the materials.

Since fluorine-containing resins represented by polytetrafluoroethylene(PTFE) are materials being free from such degradation, articles in theform of membrane such as sheet and film which comprise PTFE as a matrixresin and contain a photodegrading catalyst have been proposed (“KogyoZairyou”, July 1996 (Vol. 44, No. 8). However in those forms, aphotodegrading catalyst contained in PTFE does not function effectively,and there is a certain limit in its application to interior goods suchas curtains.

A main object of the present invention is to provide a fibrous materialhaving excellent deodorizing antibacterial property, by combining aphotodegrading catalyst having deodorizing antibacterial activity with afluorine-containing resin to make a fibrous material, thus enabling thephotodegrading catalyst to be exposed more on the surface of the fibrousmaterial, and to provide a cloth produced by using the fibrous material.

DISCLOSURE OF THE INVENTION

Namely the present invention relates to a fibrous material comprising afluorine-containing resin having a photodegrading catalyst.

A preferred photodegrading catalyst is an anatase-type titanium dioxide.It is preferable that the catalyst is contained in or adhered to thefibrous material in an amount of from 1 to 50% (% by weight, hereinafterthe same). It is particularly preferable that the catalyst is containedtherein. Adhering can be carried out by coating, impregnating or thelike. There is a case where PTFE is preferably a semi-sintered one. PTFEmay contain an adsorbent having deodorizing activity. The adsorbent maybe contained in a coating of the fibrous material.

The fibrous material is preferably in the forms mentioned below.

(1) Monofilament

(2) Staple fiber

(3) Continuous yarn split to the net-like form

(4) Finished yarn produced by mix-spinning or mix-twisting at least oneof other fibrous materials to above (1) to (3)

Among them, the monofilament and staple fiber may have branches.

The other fibrous material used for the finished yarn is preferably anactivated carbon fiber, and may contain the adsorbent or may be coatedwith the adsorbent.

Also the present invention relates to the deodorizing antibacterialcloth made of the fibrous material.

The deodorizing antibacterial cloth may comprise a non-woven fabric,woven fabric or knitted fabric made by combining at least one of theother fibrous materials. At least one of the other fibrous material maybe an activated carbon fiber or a material containing the activatedcarbon fiber, or may be a material containing the adsorbent or coatedwith the adsorbent.

Further the deodorizing antibacterial cloth may be combined with a basefabric such as a non-woven fabric, woven fabric or knitted fabric madeof other fibrous material to give a composite cloth. In that case, thebase fabric may contain an activated carbon fiber or may contain theadsorbent or be coated with the adsorbent.

BEST MODE FOR CARRYING OUT THE INVENTION

The fibrous material of the present invention basically comprises thefluorine-containing resin having the photodegrading catalyst. Examplesof the fluorine-containing resin are PTFE, PFA, FEP, ETFE and the like.Among them, PTFE is preferred. The following explanation is made basedon PTFE, but is also applicable to other fluorine-containing resins.

PTFE used in the present invention encompasses homopolymer oftetrafluoroethylene (TFE) and a copolymer of TFE and other comonomer ofat most 0.2%. Non-restricted examples of the comonomer are, forinstance, chlorotrifluoroethylene, hexafluoropropylene, perfluoro(alkylvinyl ether) and the like. Polymerization may be carried out by eitherof emulsion polymerization and suspension polymerization.

Examples of the photodegrading catalyst are anatase-type titaniumdioxide, zinc oxide, tungsten trioxide and the like. The catalyst isusually in the form of powder. Among the photodegrading catalysts,anatase-type titanium dioxide is particularly preferable from the pointsthat various malodorous substances such as ammonia, acetaldehyde, aceticacid, trimethylamine, methylmercaptan, hydrogen sulfide, styrene, methylsulfide, dimethyl disulfide, isovaleric acid and the like can bedegraded and that the degrading effect is exhibited even by weak light(ultraviolet ray).

A content of the photodegrading catalyst is preferably not less than 5%by weight from the viewpoint of rapid exhibition of deodorizingantibacterial activity and not more than 50% by weight from theviewpoint of easy molding, particularly from 10 to 40% by weight.

In the present invention, the “fibrous material” is a conceptencompassing the above-mentioned monofilament, staple fiber, split yarn,finished yarn and the like.

Examples of methods for producing those PTFE fibrous materials havingthe photodegrading catalyst are as follows.

(1) Production of monofilament

(A) Production by emulsion spinning method (cf. U.S. Pat. No. 2,772,444)

An aqueous dispersion of PTFE fine powder, photodegrading catalystpowder, surfactant and coagulant (usable coagulant coagulated underacidic condition, for example, sodium alginate) is extruded through finenozzles in an acidic bath, and a coagulated extrudate in the form offiber is dried, sintered and stretched to give a monofilament.

(B) Production by opening a film (cf. WO94/23098)

(a) Production of PTFE powder containing titanium dioxide

An aqueous dispersion of: PTFE prepared by emulsion polymerization andan aqueous dispersion of the photodegrading catalyst powder are mixed,followed by stirring or adding an agglomerating agent (adding dropwisehydrochloric acid, nitric acid or the like) and then sting toagglomerate primary particles of PTFE and at the same time to coagulatethe photodegrading catalyst powder therewith, thus giving secondaryparticles (average particle size: 200 to 1000 μm) obtained byincorporating the photodegrading catalyst powder into the agglomeratedprimary particles of PTFE. Then the secondary particles are dried toremove water and give a powder (a-1).

Another method is a method (a-2) for uniformly mixing a PTFE moldingpowder prepared by suspension polymerization and a photodegradingcatalyst powder.

In the methods (a) for producing PTFE powder containing thephotodegrading catalyst, the method (a-1) is preferable. In the method(a-1) it is possible that a larger amount of photodegrading catalystpowder is introduced (for example, 10.1 to 40% by weight), and a uniformmolded article can be produced from the obtained powder. Also when afibrous material is produced finally, the photodegrading catalyst powderis uniformly dispersed therein and excellent photocatalytical activitycan be obtained. According to that method, the photodegrading catalystpowder can be contained uniformly in a large amount (for example, morethan 30%).

(b) Production of un-sintered film

An auxiliary solvent for extrusion molding (for example, Isopar M whichis a petroleum solvent available from Exxon Chemical Co., Ltd.) is addedto the mixed powder obtained in above (a), followed by paste extrusionand calender molding to give a film. Then the auxiliary solvent forextrusion molding is dried to give an un-sintered film.

(c) Production of heat-treated film (Sintered film A, Semi-sintered filmB)

Sintered film A can be obtained by heating the un-sintered film producedin the above (b) in an atmosphere of not less than a melting point ofPTFE powder, usually from 350° to 380° C. for about two minutes orlonger.

Also a sintered film can be obtained by compression-molding the mixedpowder obtained in the above (a-2) to give a cylindrical pre-form andthen heating the pre-form at 360° C. for 15 hours, cooling and cutting.

Semi-sintered film B can be obtained by heat-treating the un-sinteredfilm of the above (b) at a temperature between the melting point (about345° to 348° C.) of an un-sintered powder and the melting point (325° to328° C.) of a sintered article.

The film can also be produced by a method of coating a dispersion of amixture of fluorine-containing resin particles and titanium dioxideparticles on a fluorine-containing resin film and then sintering, or amethod of coating the dispersion on a plate of aluminum or the like oron a polyimide film and then sintering to give a cast film.

In that case, the fluorine-containing resin particles or film maycomprise PTFE solely or a mixture with PFA and FEP, or may be acomposite film.

(d) Production of stretched film (C and D)

A stretched film (Stretched film C) can be obtained by passing Sinteredfilm A between the rolls in the longitudinal direction with heating andstretching at a stretching ratio of about 5 times by changing a relativespeed of the rolls, or a stretched film (Stretched film D) can beobtained by passing Semi-sintered film B between the rolls in thelongitudinal direction with heating and stretching at a stretching ratioof about 5 to 20 times by changing a relative speed of the rolls.

(e) Production of monofilament

A monofilament can be obtained by a method of cutting Sintered film A orSemi-sintered film B into thin strips and then stretching in thelongitudinal direction.

The monofilament having branches can be obtained by another method oftearing Stretched film C or D with rotating needle blade rolls, and alsoby a method of tearing and then dividing.

A maximum thickness of the monofilament is determined depending on astarting film. A minimum thickness of the monofilament is determined bya minimum slit width, and is about 25 tex.

(2) Production of staple fiber (cf. WO94/23098)

A staple fiber can be produced by cutting the above-mentionedmonofilament to an optional length (Preferable length is from about 25mm to about 150 mm). Also it is preferable to let the staple fiber havebranches in order to enhance entangling property of the fiber andincrease a surface area with more fine fibers. A staple fiber havingbranches can be obtained by tearing Stretched film C or D with needleblade rolls rotating at high speed.

The staple fiber has branches and crimps and can be used alone as it isor in the form of finished yarn mentioned below.

Particulars of the staple fiber obtained by the above-mentioned methodare preferably as follows, but are not restricted to them.

Fiber length: 5 to 200 mm, preferably 10 to 150 mm

Number of branches: 0 to 20/5 cm, preferably 0 to 10/5 cm

Number of crimps: 0 to 25/20 mm, preferably 1 to 15/20 mm

Fineness: 1 to 150 deniers, preferably 2 to 75 deniers

Sectional configuration: Irregular

(3) Production of split yarn (cf. WO95/00807)

A split yarn can be produced by slitting uniaxially Stretched film C orD produced in the above (d) of (1)-(B) into a ribbon form of about 5 mmto about 20 mm width and then splitting with a needle blade roll,preferably a pair of needle blade rolls.

A network structure is a structure in which the uniaxially stretchedPTFE film is not split into pieces of fibers with needle blades ofneedle blade rolls but the split film has a net-like form when extendedin the widthwise direction (in the direction crossing at a right angleto the film feeding direction).

The split yarn can be used alone as it is or in a bundled form of two ormore thereof or in the form of finished yarn mentioned below forknitting and weaving.

(4) Production of finished yarn

A finished yarn can be produced by combining the PTFE fibrous materialhaving a photodegrading catalyst and obtained in the above (1), (2) or(3) with other fibrous material.

Mix-spinning and mix-twisting can be carried out by usual methods.

Examples of the other fibrous material are an activated carbon fiber;natural fibrous materials such as cotton and wool; semi-synthetic fibersuch as rayon; synthetic fibrous materials such as polyester, nylon andpolypropylene; and the like. In case where strong odor increases rapidly(increase in gas concentration), an activated carbon fiber or the likeis preferable as the other fibrous material for a deodorizingantibacterial cloth. Examples of the activated carbon fiber are oneobtained, for example, from an acrylic fiber, and the like. It ispreferable that an amount of the PTFE fibrous material having thephotodegrading catalyst is not less than 10%, particularly not less than20% of the finished yarn from the viewpoint of exhibiting deodorizingantibacterial activity.

It is preferable to let an adsorbent having deodorizing activity existin various forms in the PTFE fibrous material having the photodegradingcatalyst of the present invention in order to enhance deodorizingefficiency. Examples of the adsorbent having deodorizing activity arefibers or particles of an activated carbon, zeolite, Astench C-150(available from Daiwa Chemical Co., Ltd.) and the like.

An amount of the activated carbon particles or zeolite particles amongthe mentioned adsorbents, when they are contained in the form of fillerin PTFE, is not more than 25%, preferably 1 to 20% based on PTFE.

Astench C-150 can be applied by coating or impregnating in the otherfibrous material which is used in the finished yarn or in production ofa cloth (mentioned below). It is preferable that coating or impregnatingof Astench C-150 is carried out by coating through usual method such asdipping or spraying by using about 10% aqueous solution of AstenchC-150, and then dehydrating and drying.

As mentioned above, the activated carbon fiber having a deodorizingactivity can be used as one of other fibrous materials for the finishedyarn. In that case, it is preferable that an amount of the activatedcarbon fiber is not more than 80%, particularly from 5 to 75% of thefinished yarn.

The PTFE fibrous material having the photodegrading catalyst of thepresent invention is applied to effectively exhibit deodorizing andantibacterial activity by its photodegrading function, is in the form ofwoven fabric, knitted fabric and non-woven fabric and is useful, forexample, as a deodorizing antibacterial cloth.

The present invention further relates to the deodorizing antibacterialcloth comprising the above-mentioned PTFE fibrous material having thephotodegrading catalyst.

The cloth of the present invention encompasses a woven fabric, knittedfabric and non-woven fabric and can be produced by usual method.

The deodorizing antibacterial cloth of the present invention may be inthe form of multi-layered cloth produced in combination with a basefabric comprising other fibrous material. The base fabric to be used maybe in any form of woven fabric, non-woven fabric and knitted fabric.Examples of preferred material of the base fabric are an activatedcarbon fiber, meta-linked type aramid fiber, para-linked type aramidfiber, PTFE fiber, polyimide fiber, glass fiber, polyphenylene sulfidefiber, polyester fiber and the like. It is particularly preferable thatthe base fabric contains an activated carbon fiber, to enhance adeodorizing effect. A content of the activated carbon fiber in the basefabric is from about 5% to about 100%, preferably from about 10% toabout 100%.

The thus produced fluorine-containing resin fibrous material of thepresent invention is used as it is or processed to desired form, as afiller for various materials or for applications such as carpet,illumination cover, reflection plate, interior cloth, blind, curtain,roll curtain, bedclothes (bed cover, pillow cover, etc.), shoji screen,wall cloth, tatami mat, window screen, air filter, filter for airconditioning, liquid filter, interior materials for vehicles (car,train, airplane, ship, etc.), net lace, clothes for medical use(operating gown, etc.), gloves for medical use (surgery gloves, etc.),curtain for bath room, paper diaper, slippers, shoes (school shoes,nurse shoes, etc.), telephone cover, sterilizing filter for 24-hourbath, foliage plant (artificial flower), fishing net, clothes, socks,bag filter, and the like. Particularly the deodorizing antibacterialcloth can be used for diaper cover, clothes such as apron, bedclothessuch as bed, mat, pillow and sheet clothes, decorative materials such ascurtain, table cloth, mat and wall cloth, and the like. Further thecloth is useful for applications in places where malodorous smelling andpropagation of bacteria are apt to arise, such as hospital, toilet,kitchen, dressing room, and the like.

Then the fibrous material and deodorizing antibacterial cloth of thepresent invention are explained based on examples, but the presentinvention is not limited to them.

EXAMPLE 1

(1) Production of PTFE powder containing titanium dioxide

A 10% aqueous dispersion containing 8 kg of PTFE particles obtained byemulsion polymerization (number average molecular weight: 5,000,000,average particle size: about 0.3 μm) and a 20% aqueous dispersioncontaining 2 kg of anatase-type titanium dioxide (Titanium Dioxide P25available from Nippon Aerosil Co., Ltd., average particle size: about 21μm) were poured continuously into a coagulation tank (capacity: 150liters, inside temperature of the tank: 30° C.) equipped with stirringblades and a jacket for adjusting temperature and then stirred to giveuniformly co-agglomerated secondary particles of PTFE particles andtitanium dioxide particles, followed by separating the co-agglomeratedparticles from water phase. Those co-agglomerated particles were driedin an oven (130° C.) to give a PTFE powder (average particle size: 500μm, apparent density: about 450 g/liter) containing titanium dioxide inan amount of 20%.

(2) Production of un-sintered film

To the PTFE powder containing titanium dioxide and obtained in the above(1) was mixed 25 parts of an extrusion molding auxiliary (petroleumsolvent Isopar M available from Exxon Chemical Co., Ltd.) based on 100parts of the powder to give a mixture in the form of paste. The pastewas extruded by paste extrusion method, and rolled with rollers,followed by drying to remove the molding auxiliary. Thus a continuousun-sintered PTFE film containing titanium dioxide and having a width of200 mm and a thickness of 100 μm was produced.

(3) Production of heat-treated film

The un-sintered PTFE film containing titanium dioxide which was producedin the above (2) was heat-treated to give Sintered PTFE film A-1containing titanium dioxide and Semi-sintered PTFE film B-1 containingtitanium dioxide.

Sintered PTFE film A-1 was obtained by heating the un-sintered PTFE filmat 360° C. for about three minutes in an oven.

Semi-sintered PTFE film B-1 was obtained by heating the un-sintered PTFEfilm for about 30 seconds in an oven of 340° C. A degree of sintering(crystalline conversion ratio) of the film B-1 was 0.4.

(4) Production of uniaxially stretched film

Sintered PTFE film A-1 was stretched 5 times in the longitudinaldirection between two pairs of heating rolls (diameter: 330 mm,temperature: 300° C.) to give Uniaxially stretched film C-1.

Also Semi-sintered PTFE film B-1 was stretched 10 times in thelongitudinal direction with the above-mentioned heating rolls to giveUniaxially stretched film D-1.

The uniaxially stretched films can be used as they are since thetitanium dioxide particles are exposed more on the surface of the filmsas compared with an un-stretched film. Further as mentioned below, byforming the films into a fiber, more preferable characteristics andapplications can be provided.

(5) Production of monofilament

Sintered PTFE film A-1 or Semi-sintered PTFE film B-1 of the above (3),after having been slit to 2 mm width, was uniaxially stretched in thesame manner as the above (4). Thus a monofilament of 200 tex having arectangular section was obtained from the film A-1 and a monofilament of100 tex having a rectangular section was obtained from the film B-1.

In addition to the method of (6) mentioned below, a staple fiber can beproduced by a method of cutting those monofilaments into short pieces.

(6) Production of staple fiber

Uniaxially stretched film C-1 or D-1 obtained in the above (4) was tornand opened according to the method of (4) of Example 5 disclosed inWO94/23098 by using a pair of upper and lower needle blade rolls at afilm feeding speed (V3) of 1.6 m/min and a peripheral speed (V4) ofneedle blade rolls of 48 m/min to give a staple fiber. The obtainedstaple fiber comprised filaments, and each filament had branches.

The sintered staple fiber obtained from Uniaxially stretched sinteredPTFE film C-1 and the semi-sintered staple fiber obtained fromUniaxially stretched semi-sintered PTFE film D-1 are assumed to be E-1and F-1, respectively.

With respect to the obtained PTFE staple fiber containing titaniumdioxide, a fiber length, the number of branches, sectionalconfiguration, fineness and the number of crimps were determined by thefollowing methods. The results are shown in Table 1.

(Fiber length and number of branches)

With respect to a hundred pieces of fibers sampled at random, the lengthand the number of branches (including loops) were measured.

(Sectional configuration)

Sectional configuration of a bundle of fibers sampled at random wasdetermined by using a scanning electron microscope.

(Fineness)

Fineness of a hundred pieces of fibers sampled at random was measuredwith an electronic fineness measuring apparatus (available from SearchCo., Ltd.) by utilizing a resonance of the fiber.

The apparatus could measure the fineness of the fibers having the lengthof not less than 3 cm, and the fibers were selected irrespective oftrunks or branches. But the fibers having, on the length of 3 cm, alarge branch or many branches were excluded because they affects themeasuring results. The apparatus was capable of measuring the finenessin the range of 2 to 70 deniers, and so the fineness exceeding 70deniers was determined by measuring the weight of the fiber. The fibershaving the fineness less than 2 deniers were excluded becausemeasurement was difficult.

(Number of crimps)

Measurement was made in accordance with the method of JIS L 1015 bymeans of an automatic crimp tester available from Kabushiki Kaisha KoaShokai with a hundred pieces of fibers sampled at random (The crimps onthe branch were not measured).

TABLE 1 Staple fiber Particulars Sintered fiber Semi-sintered fiberFiber length (mm) 11 to 105 9 to 93 Number of branches 0 to 7  0 to 5 (per 5 cm) Sectional configuration Irregular Irregular Fineness (denier)2 to 53 2 to 42 Number of crimps 0 to 4  0 to 5  (per 20 mm)

(7) Production of split yarn (cf. WO96/00807)

Uniaxially stretched sintered PTFE film C-1 was cut to 5 mm width in thelongitudinal direction, and the cut film was passed through two pairs ofneedle blade rolls provided with needle blades thereon and rotating athigh speed (peripheral speed of blade: 30 m/min) at a film feeding speedof 5 m/min to give a split yarn of 500 tex (500 g per 1 km) having anetwork structure.

(8) Production of finished yarn

Opening, mix-spinning, carding and twisting were carried out by usualmethod by using the same amount of Sintered staple fiber E-1 and rawwool to give a finished yarn of 200 tex (200 g per 1 km)

EXAMPLE 2

(Production of deodorizing antibacterial non-woven fabric)

A web was produced from Sintered PTFE staple fiber E-1 containingtitanium dioxide. The web was placed on a base fabric of meta-linkedtype aramid fiber (Product No. CO1700 available from Teijin Ltd.) sothat a weight per unit area became 200 g/m² (Sample A) and 40 g/m²(Sample B) and then needle-punched to give a non-woven fabric. Thenumber of needles was 100 needles/cm².

Also a web was produced from Semi-sintered PTFE staple fiber F-1containing titanium dioxide. The web was placed on a meta-linked typearamid fiber felt (Product No. GX-0302 available from Nippon Felt KogyoKabushiki Kaisha, weight per unit area: 350 g/m²) so that a weight perunit area became 200 g/m² (Sample C) and 40 g/m² (Sample D) and thensubjected to water jet entangling to give a multi-layered non-wovenfabric.

With respect to the obtained deodorizing antibacterial non-woven fabric(Samples A to D), the following deodorization tests were carried out.The results (rate constant k of degradation) are shown in Table 2.

(Deodorization tests)

A sample (9 cm×9 cm) is placed in a 5-liter flask (having gas inlet andoutlet), and a light source (one 6 W black light) is arranged 2 cm apartfrom the sample in parallel therewith. Then acetaldehyde is introducedinto the flask and a concentration of acetaldehyde is measured with alapse of time to determine a degradation rate of acetaldehyde.Acetaldehyde is initially introduced with a syringe so that its initialconcentration is about 20 ppm. A change in concentration with a lapse oftime is measured at intervals of one minute with a gas monitor(multi-gas monitor of model 1302 available from B & K Corp).

The concentration C after a lapse of t minute is represented by thefollowing equation.

C=C ₀ e−kt

in which C_(o) is an initial concentration, e is a natural logarithm andk is a rate constant of degradation. The larger the value k (ppm/sec)is, the higher the degrading activity for acetaldehyde is.

For comparison, the following Films A to D were produced, and the samedeodorization tests were carried out. The results are shown in Table 2.

Film A: Uniaxially stretched (5 times) sintered PTFE film containing 20%of titanium dioxide (weight: 200 g/m²)

Film B: Uniaxially stretched (5 times) sintered PTFE film containing 20%of titanium dioxide (weight: 40 g/m²)

Film C: Uniaxially stretched (10 times) semi-sintered PTFE filmcontaining 20% of titanium dioxide (weight: 200 g/m²)

Film D: Uniaxially stretched (10 times) semi-sintered PTFE filmcontaining 20% of titanium dioxide (weight: 40 g/m²)

TABLE 2 Rate Constant k of Weight per unit area Degradation Articlestested (g/m²) (×10⁻⁵) Sintered PTFE Sample A 200 153 Film A 200 3.82Sample B 40 96.1 Film B 40 43.6 Semi-sintered PTFE Sample C 200 201 FilmC 200 5.28 Sample D 40 121 Film D 40 63.5

As is clear from Table 2, the degradation rate of acetaldehyde isincreased greatly when the non-woven fabrics are produced from thefibrous material of PTFE containing titanium dioxide. Thereby it isrecognized that an excellent deodorizing effect is exhibited.

EXAMPLE 3

(Production of deodorizing antibacterial non-woven fabric)

A web was obtained from the Sintered PTFE staple fiber E-1 containingtitanium dioxide, and placed on a felt of activated carbon fiber(Kuractive available from Kuraray Co., Ltd., weight per unit area: 150g/m²) so that a unit weight became 100 g/cm². Then needle punching wascarried out with 100 needles/cm² to give a multi-layered non-wovenfabric.

Deodorization tests were carried out in the same manner as in Example 2by using the obtained non-woven fabric. Two minutes after startingemission of light, the concentration of acetaldehyde decreased to ahalf. Due to the remarkable decrease in the concentration, the rateconstant k of degradation could not be determined.

EXAMPLE 4

(Production of deodorizing antibacterial woven fabric)

A plain-woven fabric (400 g/m²) was produced by using the sintered PTFEsplit yarn containing titanium dioxide which was obtained in the above(7), as a weft and a polyester fiber finished yarn of 20 tex (20 g per 1km) as a warp.

Deodorization tests were carried out in the same manner as in Example 2by using the obtained woven fabric. The rate constant k of degradationwas 171×10⁻⁵.

EXAMPLE 5

(Production of deodorizing antibacterial woven fabric)

A twill-woven fabric (500 g/m²) having two wefts was produced by usingthe finished yarn of sintered PTFE containing titanium dioxide which wasobtained in the above (8).

Deodorization tests were carried out in the same manner as in Example 2by using the obtained woven fabric. The rate constant k of degradationwas 135×10⁻⁵.

REFERENCE EXAMPLE

Comparison between a co-agglomerated powder and a dry blend powder

[Preparation of co-agglomerated powder]

A 50-liter stirring tank was charged with an aqueous dispersion of PTFEparticles (average particle size: 0.3 μm, number average molecularweight: 5,000,000, concentration: 10% by weight, equivalent to 4 kg ofPTFE) obtained by emulsion polymerization of TFE and an aqueousdispersion of titanium dioxide particles (titanium dioxide P-25available from Nippon Aerosil Co., Ltd., concentration: 10% by weight,equivalent to 1 kg of titanium dioxide), followed by mixing and stirringto give a co-agglomerated product of PTFE and titanium dioxide. Theco-agglomerated product was then dried in a drying oven of 150° C. Theobtained powder was assumed to be “Powder {circle around (1)}” (titaniumdioxide content: 20% by weight, average particle size of the powder: 440μm, apparent density of the powder: 0.45).

[Preparation of dry blend powder]

In the same manner as mentioned above, a 50-liter stirring tank wascharged with an aqueous dispersion of PTFE particles (average particlesize: 0.3 μm, number average molecular weight: 5,000,000, concentration:10% by weight, equivalent to 5 kg of PTFE) obtained by emulsionpolymerization of TFE, followed by mixing and stirring to give anagglomerated product of PTFE. The agglomerated product was then dried ina drying oven of 150° C. (average particle size of the powder: 450 μm,apparent density of the powder: 0.45).

Subsequently the PTFE powder and titanium dioxide powder were mixed byshaking in a 2-liter wide neck polyethylene bottle to give a powdermixture of 500 g. A powder mixture obtained by blending titanium dioxidein an amount of 5% by weight based on the PTFE powder is assumed to be“Powder {circle around (2)}” and a powder mixture obtained by blendingtitanium dioxide in an amount of 20% by weight based on the PTFE powderis assumed to be “Powder {circle around (3)}”.

[Mixing of molding auxiliary]

Powder {circle around (1)} was put in a 2-liter wide neck polyethylenebottle, and then 25 parts by weight of the molding auxiliary Isopar M(petroleum solvent available from Exxon Chemical Co., Ltd.) was addedthereto, the same procedures being conducted to each of Powder {circlearound (2)} and {circle around (3)}.

[Results of molding of each powder]

Each powder mentioned above was evaluated with respect to moldability bypaste extrusion (appearance of extrudate) with a die mold having acylinder diameter of 50 mm and a die diameter of 6 mm; calenderingproperty of the extrudate by calender rolls (appearance in case ofmaking a thickness to 100 μm); stretchability of the sintered rolledfilm (sintering temperature: 370° C.) (whether or not the film can bestretched 5 times under the conditions of the film width of 20 mm, chucktube of 50 mm and stretching temperature of 300° C.); and a state ofdistribution of titanium dioxide on the film (samples were collected atrandom from five points of the film and scanned with a X-ray microanalyzer having a magnification of 50 times that of an electronmicroscope). The results are shown in Table 3. From the results shown inTable 3, it is seen that the co-agglomerated product is superior.

TABLE 3 Powder {circle around (1)} Powder {circle around (2)} Powder{circle around (3)} Moldability Normal Abnormal Abnormal by pasteExtrudate had Meandering of Cracking extrusion linearity extrudateoccurred in occurred places of a surface of extrudate Calendering NormalAbnormal Abnormal property Stable long film Unstable film Sometimes filmwidth being cut Stretchability Normal Abnormal Abnormal Stretched stably2 To 3 pieces of All samples were 10 samples were broken during brokenin stretching average Distribution of Uniform Slightly Significantlytitanium non-uniform non-uniform dioxide

What is claimed is:
 1. A fibrous material comprisingpolytetrafluoroethylene having a photodegrading catalyst, wherein thephotodegrading catalyst is contained in an amount of 1 to 50% by weight,the photodegrading catalyst comprises anatase-titanium dioxide, and thepolytetrafluoroethylene is a semi-sintered polytetrafluoroethylene. 2.The fibrous material of claim 1, wherein further an adsorbent havingdeodorizing activity is contained.
 3. The fibrous material of claim 1,wherein fibrous material is coated with an adsorbent having deodorizingactivity.
 4. The fibrous material of claim 1, wherein the fibrousmaterial is in the form of monofilament.
 5. The fibrous material ofclaim 1, wherein the fibrous material is in the form of staple fiber. 6.The fibrous material of claim 1, wherein the fibrous material has abranch.
 7. The fibrous material of claim 1, wherein the fibrous materialis a continuous yarn which is split to a net-like form.
 8. The fibrousmaterial of claim 1, wherein the fibrous material is a finished yarnproduced by mix-spinning or mix-twisting with at least one of otherfibrous materials.
 9. The fibrous material of claim 8, wherein at leastone of said other fibrous materials is an activated carbon fiber. 10.The fibrous material of claim 8, wherein at least one of said otherfibrous materials contains an adsorbent having deodorizing activity, oris coated with the adsorbent.
 11. A deodorizing antibacterial clothcomprising the fibrous material of claim
 8. 12. A deodorizingantibacterial cloth comprising a non-woven fabric, woven fabric orknitted fabric produced by combining the fibrous material of claim 8with at least one of other fibrous materials.
 13. The deodorizingantibacterial cloth of claim 12, wherein at least one of said otherfibrous materials contains an activated carbon fiber.
 14. Thedeodorizing antibacterial cloth of claim 12, wherein at least one ofsaid other fibrous materials contains an adsorbent having deodorizingactivity, or is coated with the adsorbent.
 15. A multi-layereddeodorizing antibacterial cloth produced by combining the deodorizingantibacterial cloth of claim 1 with a base fabric of a non-woven fabric,woven fabric or knitted fabric comprising other fibrous material. 16.The multi-layered deodorizing antibacterial cloth of claim 15, wherein apart of or a whole of other fibrous material of said base fabriccontains an adsorbent having deodorizing activity, or is coated with theadsorbent.
 17. The multi-layered deodorizing antibacterial cloth ofclaim 15, wherein other fibrous material of said base fabric is anactivated carbon fiber.
 18. The fibrous material of claim 1, wherein thefibrous material is obtained from a powder comprising PTFE secondaryparticles containing the photodegrading catalyst which are prepared byco-agglomerating in coexistence of the photodegrading catalyst at thetime of agglomeration of PTFE primary particles in an aqueousdispersion.
 19. A multi-layered deodorizing antibacterial cloth producedby combining the deodorizing antibacterial cloth of claim 12 with a basefabric of a non-woven fabric, woven fabric or knitted fabric comprisingother fibrous material.